Although dispositional optimism has been linked to a number of health outcomes including enhanced postsurgical recovery, the physiological pathways are not well understood. The two studies in this project address the influences of optimist and mood on neuroendocrine and immune function and wound healing, and the extent to which relaxation-based interventions may modulate these relationships; suction blister protocols will provide a mechanism for studying the inflammatory responses in vivo. The subjects of Study 1, 180 men and women who range in age from 18 to 80, will be admitted to the Ohio State Clinical Research Center (GCRC) for 26 hours. Half of the subjects will be randomly assigned to a relaxation intervention, with the first session beginning prior to the initiation of the blister wounds, and all participants will be followed after discharge to assess the healing of the blister would sites. To evaluate the extent to which relaxation can buffer the effects of an acute stressor, the 80 medical students who comprise the sample in Study 2 will undergo the blister wound procedure during each of two GCRC admissions, once at a lower stress "baseline," and again 2-3 days before a key exam, and they will be followed daily to assess blister site wound repair after both admissions. Half the subjects will be randomly assigned to receive relaxation training beginning a week prior to the second GCRC admission. The specific aims of the proposed studies are to (1) assess the linkages among dispositional optimism, expectancies, mood, hormones, and production of proinflammatory cytokines, as well as the extent to which relaxation, age and gender mediate these relationships; (2) determine the relationships between hormones and production of these pathways; (3) assess relationships between proinflammatory cytokines from peripheral blood and blister chamber fluid and the healing of blister sites, and (4) determine the extent to which age interacts with optimism and mood to impair cytokine secretion and healing.